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Home >> Mercury >> 2005 >> Montego Premier, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Pinpoint Test JE: Integrated Ignition Coil Pack A, B, Or C Failure Through Pinpoint Test KP: Charge Air Cooler (CAC) Pump - (Except Diesel & Hybrid) >> Pinpoint Test KN: Variable Speed Electric Cooling Fan >> Test Procedure

Test Procedure

  1. KN1 KOEO DTC P0480: CHECK THE B+ AND GND CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Key in OFF position.
    • CF Motor connector disconnected.
    • Rotate the fan by hand. The fan should rotate freely, with no abnormal binding. If binding is present, remove any foreign materials or install a new fan assembly as required.
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-) CF Motor Connector, Harness Side
      B+ GND

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KN3. GO to  KN2.
  2. KN2 CHECK VOLTAGE TO FAN MOTOR USING CHASSIS GROUND AS A REFERENCE 
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-)
      B+ Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    REPAIR the open circuit.
    Open GND harness circuit    		 B+ circuit fault. CHECK the condition of the related fuse/fuse links. If OK, REPAIR the open circuit. If the fuse/fuse link is damaged, CHECK the circuit for short to ground before replacing.
  3. KN3 CHECK THE FCV CIRCUIT(S) 
    • Connect the 1.6K ohms resistor between the FCV and B+ circuits at the CF harness connector (this simulates cooling fan circuitry).
    • Key in ON position.
    • Check for KOEO DTCs:

    Is DTC P0480 present? 

    Yes No
    Key in OFF position.
    GO to  KN4.    		 Key in OFF position. INSTALL a new cooling fan motor.
  4. KN4 CHECK THE FCV CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • PCM connector disconnected.
    • Key in ON position.
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-)
      FCV Ground

    Is the voltage less than 1 V? 

    Yes No
    Key in OFF position.
    GO to  KN5.    		 Key in OFF position. REPAIR the short circuit.
  5. KN5 CHECK THE FCV CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
      CF Motor Connector, Harness Side (-)
      FCV Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KN6. REPAIR the short circuit.
  6. KN6 CHECK FOR AN OPEN CIRCUIT BETWEEN PCM & FCV 
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-) CF Motor Connector, Harness Side
      FCV FCV

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . REPAIR the open circuit.
  7. KN7 CONTINUOUS MEMORY DTC P0480: CHECK THE B+ & GND CIRCUIT FOR AN INTERMITTENT CONCERN 
    • Key in OFF position.
    • CF Motor connector disconnected.
    • Rotate the fan by hand. The fan should rotate freely, with no abnormal binding. If binding is present, remove any foreign materials or install a new fan assembly as required.
    • Connect a non-powered test lamp between:
      (+) CF Motor Connector, Harness Side (-) CF Motor Connector, Harness Side
      B+ GND
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns Off when a fault is detected.
      • Shake, wiggle, and bend the B+ and GND circuits to the CF.
      • Shake, wiggle, and bend the associated fuse.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. GO to  KN8.
  8. KN8 CHECK THE FCV CIRCUIT(S) FOR INTERMITTENT CONCERNS 
    • Connect the 1.6 K ohms resistor between the FCV and B+ circuits at the CF harness connector (this simulates cooling fan circuitry).
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-)
      FCV Ground
    • Key in ON position.
    • Enter output test mode. Refer to OUTPUT TEST MODE (OTM) .
    • Command the low speed fan ON.
    • Observe the DMM for an indication of a fault while completing the following. Note that voltage changes suddenly when a fault is detected.
      • Shake, wiggle, and bend the FCV circuit between the CF motor and the PCM.

    Is a fault indicated? 

    Yes No
    Key in OFF position.
    ISOLATE the fault and REPAIR as necessary.    		 Key in OFF position.
    GO to PINPOINT TEST Z STEP 1 .
  9. KN9 COOLING FAN MOTOR DOES NOT OPERATE (WITH NO DTCS): COMMAND THE FAN ON TO CHECK OPERATION 
    • Carry out the KOEO self-test.
    • Listen to the fan.

    Does the fan operate sometime during the KOEO self-test? 

    Yes No
    Key in OFF position.
    Concern is elsewhere. RETURN to SYMPTOM CHARTS - GASOLINE MODELS for further direction.    		 Key in OFF position.
    GO to  KN10.
  10. KN10 CHECK THE B+ AND GND TO COOLING FAN MOTOR B+ & GND 
    • CF Motor connector disconnected.
    • Rotate the fan by hand. The fan should rotate freely, with no abnormal binding. If binding is present, remove any foreign materials or install a new fan assembly as required.
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-) CF Motor Connector, Harness Side
      B+ GND

    Is the voltage greater than 10.5 V? 

    Yes No
    INSTALL a new cooling fan motor. GO to  KN11.
  11. KN11 CHECK VOLTAGE TO COOLING FAN USING CHASSIS GROUND AS A REFERENCE 
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-)
      B+ Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    REPAIR the open circuit. B+ circuit fault. CHECK the condition of the related fuse/fuse links. If OK, REPAIR the open circuit. If the fuse/fuse link is damaged, CHECK the circuit for short to ground before replacing.
  12. KN12 KOEO DTC P0480: CHECK THE B+ AND GND TO COOLING FAN MOTOR 
    • Key in OFF position.
    • CF Motor connector disconnected.
    • Rotate the fan by hand. The fan should rotate freely, with no abnormal binding. If binding is present, remove any foreign materials or install a new fan assembly as required.
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-) CF Motor Connector, Harness Side
      B+ GND

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KN14. GO to  KN13.
  13. KN13 CHECK VOLTAGE TO FAN MOTOR USING CHASSIS GROUND AS A REFERENCE 
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-)
      B+ Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    REPAIR the open circuit.
    Open GND harness circuit    		 B+ circuit fault. CHECK the condition of the related fuse/fuse links. If OK, REPAIR the open circuit. If the fuse/fuse link is damaged, CHECK the circuit for short to ground before replacing.
  14. KN14 CHECK THE VPWR VOLTAGE TO CF 
    • CF Motor connector disconnected.
    • Key in ON position.
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-)
      VPWR Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    Key in OFF position.
    GO to  KN15.    		 Key in OFF position. REPAIR the open circuit.
  15. KN15 CHECK THE FCV CIRCUIT(S) TO THE FAN 
    • Connect the 1.6 K ohms resistor between the FCV and B+ circuits at the CF harness connector (this simulates cooling fan circuitry).
    • Key in ON position.
    • Carry out the KOEO self-test.

    Is DTC P0480 present? 

    Yes No
    GO to  KN16. Key in OFF position. INSTALL a new cooling fan motor.
  16. KN16 CHECK THE FCV CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • PCM connector disconnected.
    • Key in ON position.
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-)
      FCV Ground

    Is the voltage less than 1 V? 

    Yes No
    Key in OFF position.
    GO to  KN17.    		 Key in OFF position. REPAIR the short circuit.
  17. KN17 CHECK THE FCV CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
      (+) CF Motor Connector, Harness Side (-)
      FCV Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KN18. REPAIR the short circuit.
  18. KN18 CHECK THE FCV CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
      (+) CF Motor Connector, Harness Side (-) PCM Connector, Harness Side
      FCV FCV

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . REPAIR the open circuit.
  19. KN19 CONTINUOUS MEMORY DTC P0480: CHECK THE B+ & GND FOR AN INTERMITTENT CONCERN 
    • Key in OFF position.
    • CF Motor connector disconnected.
    • Rotate the fan by hand. The fan should rotate freely, with no abnormal binding. If binding is present, remove any foreign materials or install a new fan assembly as required.
    • Connect a non-powered test lamp between:
      (+) CF Motor Connector, Harness Side (-) CF Motor Connector, Harness Side
      B+ GND
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns Off when a fault is detected.
      • Shake, wiggle, and bend the B+ and GND circuits to the CFM.
      • Lightly tap on the associated FUSE to simulate road shock.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. GO to  KN20.
  20. KN20 CHECK THE VPWR CIRCUIT(S) FOR INTERMITTENT CONCERNS 
    • Key in OFF position.
    • CF Motor connector disconnected.
    • Connect a non-powered test lamp between:
      (+) CF Motor Connector, Harness Side (-)
      VPWR Ground
    • Key in ON position.
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns off when a fault is detected.
    • Shake, wiggle, and bend the VPWR circuit(s).

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. GO to  KN21.
  21. KN21 CHECK THE FCV CIRCUIT(S) FOR INTERMITTENT CONCERNS 
    • Connect the 1.6 K ohms resistor between the FCV and B+ circuits at the CF harness connector (this simulates cooling fan circuitry).
    • Measure the voltage between:
      (+) CF Motor Connector, Harness Side (-)
      FCV Ground
    • Key in ON position.
    • Enter output test mode. Refer to OUTPUT TEST MODE (OTM) .
    • Command the low speed fan ON.
    • Check DMM for an indication of a fault while completing the following. The voltage changes suddenly when a fault is detected.
    • Shake, wiggle, and bend the FCV circuit between the CF motor and the PCM.

    Is a fault indicated? 

    Yes No
    Key in OFF position.
    ISOLATE the fault and REPAIR as necessary.    		 Key in OFF position.
    GO to PINPOINT TEST Z STEP 1 .
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